G. De Mercato

New simple procedure to determine the threshold voltage of MOSFETs

Abstract A new alternative technique is proposed to extract the threshold voltage from the subthreshold-to-strong inversion transition region of MOSFETs. It uses an auxiliary operator that involves integration of the drain current as a function of gate voltage. Tests show that the procedure produces results comparable to conventional methods.

A new approach to extract the threshold voltage of MOSFETs

A new method is presented to extract the threshold voltage of MOSFETs. It is developed based on an integral function which is insensitive to the drain and source series resistances of the MOSFETs. The method is tested in the environments of circuit simulator (SPICE), device simulation (MEDICI), and measurements.

Eliminating parasitic resistances in parameter extraction of semiconductor device models

A network theorem based on potential functions is used for the purpose of cancelling the detrimental effect that the presence of parasitic linear elements has on procedures used for extracting the intrinsic-model parameters of semiconductor devices. The method is based on the use of an auxiliary function: the difference between the content and the co-content functions of the device. The theorem states that, for any arbitrarily connected network of linear and nonlinear branch elements, the summation of the difference functions of each of the branches is zero, and that this difference function is zero at any branch represented by a linear I-V characteristic. In establishing this theorem we also show that: (a) the summation of the contents, over all the branches, is zero; and (b) the summation of the co-contents, over all the branches, is zero. To illustrate the procedure the intrinsic model parameters of a real p-n junction are extracted using this idea.

Correlation between low-frequency electric conductivity and permittivity in the diaphysis of bovine femoral bone

The relationship between the low-frequency electric properties in the axial, tangential, and radial directions along the diaphysis of a femoral bovine bone is presented. It is shown that below 1 MHz the relative permittivity of the diaphysis exhibits a significant positive correlation with respect to the low-frequency conductivity, as measured in any direction, and therefore it could be related to the amount of fluid contained in the channels that provide low-frequency electrical connectivity in the measurement direction. There is no significant correlation between permittivity, in either of the three measurement directions, and the total fluid volumetric fraction in the bone. >

Dielectric properties of fluid-saturated bone: a comparison between diaphysis and epiphysis.

OJEMAN, R. G. and BLACK, P. M. (1982) Hydrocephalus in adults. In Neurological surgery. YOUMANS, J. R. (Ed.), W. B. Saunders Co., Vol. E, Chap. 37, 1423-1435. SORV.K, S., BEAR, J. and KAgNI, Z. (1988) A non-steady cornpartmental flow model of the cerebrovascular system. J. Biomech., (in press). SYMON, L. and HINZPETER, T. (1976) The enigma of normal pressure hydrocephalus: tests to select patients for surgery and to predict shunt function. Clin. Neurosurg., 24, 285-315.

Variation of the electric properties along the diaphysis of bovine femoral bone.

A preliminary study is presented of the variability of the electric properties, in the axial, tangential and radial directions, as a function of position in the diaphysis of a femoral bovine bone. The measurements were carried out at three frequencies: 100 Hz, 10 kHz and 1 MHz. It is shown that both the conductivity and the permittivity exhibit significant variations along the diaphysis, and increase in magnitude towards the epiphyses. From this study, the variation of the electric properties cannot be clearly and directly ascribed to the longitudinal variability of the total volumetric fluid content of the bone. The results reflect the orthotropic nature of the electric properties, at any given location, and indicate a position-dependent tendency towards axis symmetry.

Modeling real junctions by a series combination of two ideal diodes with parallel resistance and its parameter extraction

Abstract A technique is proposed to extract the reverse saturation current parameter and ideality factor of semiconductor junctions from the low forward voltage region of the device’s characteristics, even under the presence of significant parallel resistance effects. The series combination of two ideal diodes is proposed for modeling real devices with a non-linear contact resistance, in which case, the effective ideality factor at high voltage is higher than that of low voltage. It is proved, under certain physical assumptions, that the series combination of two ideal diodes can be modeled as a single effective diode for low voltage and another effective diode for high voltage. Both techniques were tested and their accuracy verified on experimental and simulated I–V characteristics.

The development of integration-based methods to extract parameters of two-terminal device models

We present a historic overview of the initial motivating ideas, original foundations, and subsequent development, of integration-based methods which are currently used to extract semiconductor device model parameters, as well as to assess devices¿ and circuits¿ non- linearity. To illustrate these methods¿ capabilities, in this paper we review sample applications specifically focusing on two-terminal devices, such as non-ideal junctions, illuminated solar cells, and post-breakdown conduction through thin oxides. Additional applications of these integration-based extraction methods, pertaining to MOSFET models and harmonic distortion evaluation, are presented elsewhere in this conference.

A new method for extracting the effective channel length of MOSFETs

A new and simple method to extract the effective channel length Leff of metal-oxide superconductor field effect transistor (MOSFET)s is presented. The method, which is developed based on an auxiliary integral function, has the advantage of determining the value of Leff not influenced by the series resistances of the MOSFET. The method is tested in the environments of device simulation and measurements. In addition, comparison is made between the results obtained from the present method and a widely used Leff extraction method.

On the extraction of the threshold voltage of MOSFETs

A new method to extract the threshold voltage and the effective channel of MOSFETs, which is insensitive to the series resistances, is presented. This method, which is weakly dependent on the mobility model, is tested in circuit simulator and measurement environments.